How long is too long

My partner and I have been together for 6 years. The last few year the bedroom has gotten very quiet. The first 3ish years we'd both ask for it several times a week, if not back to back days. I remember having conversations about how most new relationships seem to get to the 6 month mark and the butterflies are already kinda gone. Not us, we were years in still going at it. Now I understand that as time goes on, things slow down, maybe not for everyone, or maybe I'm making excuses, or maybe it's a little of both. I'm 40(m) she's 37(f), but I've brought this up before, and like most things, it's better for a bit, until you realize it's not. I don't think we've gone much past 2 months, definitely not 3, but that's still a long time. Within the last 6 months I even decided I wouldn't initiate it cause I wanted to see if she would. Emotions got the best of me and I didn't wanna push it off any longer so I initiated it. Moral of the story, I don't think she's intiated anything once in the last few years. It's worth noting that she doesn't turn me down, but as a man, that's one thing that I think we need, to feel wanted in that way. We can deal with a lot of neglect in other forms, but that's 1 thing that WILL break a man. I've been married twice before, she hasn't but has been in serious long term relationships, and has 2 kids, I have 3. I brought this back up today, if she's happy in our relationship, lack of sex is a big indicator things aren't right, at least in my experience. Coupled with previous trauma, my mind can spiral in some real shitty ways. She says she is, she says she wants to be with me forever and there's absolutely nothing wrong. She went on to ask me what my expectations are, as far as how often. I don't have a number. I just said Im not necessarily mad about how often, or un-often, it is, which I'm not, just that I wanna make sure we're ok from her perspective. I said I don't remember the last time she initiated it. She said that maybe it's a issue with disconnecting from the stress of kids, life and work, but I don't really believe that. Since the conversation went so well, sarcasm, I've continued to spiral while I smile and go back to acting like everything is fine. At this point in life, im on my 3rd marriage, I'm ready to give up completely. And while I know part of that is just being in my head, I've told myself if this relationship doesn't work that I'm truly done. The fact that she was "genuinely" asking me what my expectations were, as far as how often, tells me she basically has no desire to do it. It's literally the same every single time, and while it's great when it happens, I'm almost tired of doing it while still wanting it at the same time. Just typing this out is really got me questioning everything. Obviously whoever reads this is gonna have more questions, feel free to ask, but this would be a novel if I put in our life over the last 3 years. Just to be clear, there's never been infidelity, or other people of any kind. She's been through some seriously bad relationships, as have I, which makes this make even less sense since she knows how important all of these things are already as we've both have had many long talks about past issues.jusy wondering what I should do here. Is there even anything to do?

Tl;Dr wife and I have sex 1x every few months. Wife says everything is fine, she's happy, but she hasn't initiated anything herself in well over a year or two, while the first 3ish years was multiple times a week. Although she doesn't initiate it, I'm not turned down when I do. Where do I go from here.